Class.forName not working in Java RMI call

Question

Hi, What effect will Java RMI have on the following line of code?

Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

Its not working for me in an RMI call. I am new to java and RMI so please elaborate your answer in detail.

Edit:

//String connect to SQL server
String url = "jdbc:sqlserver://" + strServerIPAddress + ":1433" + ";DatabaseName=" + strDatabaseName;

try {

    Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

} 
catch (java.lang.ClassNotFoundException e) 

{ 
    System.out.println(e.getCause().toString());
    return false;
}

I have pasted the code. Can you please tell how to get the full stack trace?

Here is the batch file that I use to run the my code

% I am in my source code dir

javac -d classes -cp classes *.java
rmic -classpath classes -d classes myrmi.DummyImpl myrmi.BookImpl    
start rmiregistry -J-Dsun.rmi.loader.logLevel=VERBOSE

start java -cp classes -Djava.rmi.server.codebase=file:///C:\NetBeansProjects\MyProject\src\myrmi\classes\ -Djava.security.policy=java.policy 

myrmi.Server SEB 
start java -cp classes -Dsun.rmi.loader.logLevel=VERBOSE  -Djava.security.policy=java.policy myrmi.Client

Answer 1

When using Class.forName() the string passed to the method must contain a class that is present in your classpath.

Answer 2

Is the JAR file with the com.microsoft.sqlserver.jdbc.SQLServerDriver available on the classpath of the VM where the remote instance in running?

-cp classes will only grab the .class files under there, so if the SQLDriver is in a JAR or ZIP file (which is where it likely is) then it will not be found. You would need to do "-cp classes;< path to driver >"

Answer 3

The probable cause is that your don't have permissions to either load the driver or connect to the remote database. Roughly speaking, all the frames on the stack and for the point the current thread was created must have the required permissions (java.security.AccessController.doPrivileged can be used to play about with this). There are some debug option that can be set through system properties for showing security checks (see the source in or around AccessController).

I am unsure as to where you are trying to make the connection. If it is from code dynamically loaded by RMI, that's a weird thing to do.

You can get a full stack trace from an exception with exc.printStackTrace().